Electric water heater



May 6, 1947. R. A. JoHNsToNE ELECTRIC WATER HEATER VFiled July 1l, 1945INVENTOR.

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Patented May 6, 1947 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to improvements in electric water heatersprimarily for non-storing domestic service, to heat the water owingthrough a distributing or conductor line for a period the line is openfor water connection.

An object of the invention is Ato provide a tubular water locating coilinterposed between electric heater units, the tube alternately indentedor compressed at intervals to condense or flatten its passage foreffecting relatively opposite angular or tapering intervals, todivergently spread the water stream for increasing its rate of heatabsorption, and ruffle its flow, thereby heat the moving stream of waterto a higher degree of temperature for a given volume and period thanwould be otherwise possible. It also provides for an increased area ofexposure, more direct to the heat radiating or dissipated from theelectric heating units disposed externally of and at opposite sides ofthe water coil and with the water coil are housed within a heatinsulation lined enclosure.

Various other features and advantages of the invention will be morefully set forth in the following description of the accompanyingdrawings, forming a part hereof and depicting a preferred embodiment, inwhich:

Figure 1 is a plan view of the tubular water heating coil.

Figure 2 is a central section through the Water heater unit, taken online 2, Figure 1.

Figure 3 is an enlarged central longitudinal section of a portion of thewater coil tubing.

Figure 4 is a section on line 4 4, Figure 3.

Referring to the drawings, l indicates a water heating coil, comprisinga tube, spirally bent, with the convolutions in a common plane, with itsinner end, as an inlet connecting with a hollow tting 2, as the axis forthe coil and to which a Water service pipe or conductor connects andextends laterally therefrom. The outlet end preferably extends radiallyfrom the core, which however is optional. The number of coilconvolutions is optional and governed by the capacity and size of unit,

The tubing at determined intervals is indented or compressed in relativealternate arrangement progressively, for its length, to flatten itspassage from a cylindrical to an oblong contour, to spread and level theWater stream flowing therethrough materially stimulating and speedingits heat absorption. In alternately indenting or compressing the tube,the flattened portions 3, progressively are relatively angularlydisposed, and as shown, preferably, each at right angles to the next inorder and the distance spacing from center to center for a water supplypipe size for a conventional household plumbing fixture for example,averages about one and one-half inches apart. This tends to spiral theflow and rullie the water materially increasing the rate and degree 0fheating for a determined volume and rate of flow in the relatively shortperiod it moves through the heating Zone. The structure of the coil at afull volume and rate of flow will heat the water above the usual averagetemperature required for bath and household sink service and at acomparatively reduced kilowatt electric energy demand to be economical.

The water heating coil is disposed between a pair of electric heaterunits 4, il, of conventional construction, and as illustrated eachcomprises a coiled wire heating element 5, imbedded in a spiral grooveor channel in a face side of a refractory plate or disk, with theheating element adjoining the water coil, either suitably spaced orinsulated therefrom. The water coil and heating unit may be boundtogether by an annular rim and enclosed in a suitable casing 1, heatinsulation lined.

The heating elements when the unit is installed are in electric circuitconnection with an automatic waterow controlled switch, not illustrated,for appropriately cutting on and off the electric power, coincidentlywith the water service control, as by a valve of the plumbing fixtureand through which the Water flow and consequently the temperature canalso be controlled.

The heater is compact and eflicient and can be installed directly in anexposed section of a Water conductor line as for a laboratory or othertype of domestic or household plumbing fixture.

Having described my invention, I claim:

1. A non-storing domestic Water heater, comprising: a water heatingtubular coil, with the convolutions of the coil in a common plane, thetube depressed and flattened at determined spaced intervals toalternately convert the same from a cylindrical to an oblong contour, tothinly spread and level the Water passage, an electric heater unit offlat form, one respectively disposed at each of the opposite sides ofthe water coil and a heat insulation lined casing enclosing said coiland electric heater-units.

2. A non-storing domestic wateln heater, comprising: a Water heatingtubular coil, with the convolutions of the coil in a common plane, thetube depressed and flattened at determined spaced intervals. toalternately convert the same from a cylindrical to an oblong contour tothinly spread and level the water passage, the flattened portions intheir consecutive order relatively at an angle to one another, anelectric heater unit of at form, one respectively disposed at each ofthe opposite sides of the Water coil and a heat insulation lined casingenclosing said coil and electric heater units.

3. A water heater, comprising: a tubular Water conducting coil of flatform, electric heater elements at relative opposite sides of the coil,the length of the tube of the coil depressed at intervals to spread andnatten the same and a heat insulation lined casing enclosing said Waterconducting coil and electric heating elements.

4. A water heater, comprising: a tubular Water conducting coil of atform, the length of the tube of the coil depressed at intervals toconverge its Walls, electric heater elements external of the coil and atopposite sides thereof and an insulation lined casing enclosing saidcoil and electric heating elements.

5. A water heater, comprising: a tubular Water conducting coil of flatform, the length of the tube of the coil depressed at intervals toconverge its Walls and oblong the contour and bore of the tubecross-Wise thereof and consecutively relative at different angles,electric heater elements external of the coil and at opposite sidesthereof and an insulation lined casing enclosing said coil and electricheating elements.

6. A Water heater comprising: a tubular water conducting tube of natspiral form, the tube de formed at intervals to oblong its contour andbore transversely of the tube successively relatively at right angles toone another and opposing converging the tube between consecutiveintervals, electric heater units respectively disposed at relativeopposite sides of the coil and a casing enclosing coil and electricheater units.

ROBERT A. JOHNSTONE.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Nuniber Name Date 1,418,011 Mehn May 30, 19221,847,489 Lonergan Mar. 1, 1932 678,314 Hill July 9, 1901 2,116,896Hudson May 10l 1938 1,005,395 Wohl et al Oct. 10, 1911 1,210,691 PooleJan. 2, 1917 1,370,619 Whitehead Mar. 8, 1921

